Building a career in music is tough. And anything but simple. It always was and it is even more so now. In the pre-digital days, there was a system - a crappy, bloated, intentionally complex system - but a system nonetheless. It was still gambling, but there were winners and everyone played by the same rules. But now, we still have the vestiges of that system and we aren't sure what is necessary or valuable and what is just desperately hanging on to the past. There are fewer and fewer winners and the rules are all but gone.
So you have to find your own way. Create your own path. There isn't a book or a website or a person who can wrap it up in 100 pages or a lunch meeting and tell you what will work for you. But find good people and good sources that give you insights and principles and guidelines that you can then apply to your career and your life. There is no "new model" and there are no pre-fab answers for how to make it in music. So know what you want. Read, listen, learn, and work your ass off. Look for opportunities and jump on them when you see them. And tweak it as you go, focusing on the things that do work and throwing out the things that don't. I'm sorry. I know you want something short, sweet and concrete, but sometimes the truth just doesn't fit into 160 characters.